1. Field of the Invention
The present invention relates to a wavelength converter applicable to a network based on wavelength-division multiplexing (WDM) transmission in optical communication systems.
2. Description of the Related Art
Because of the developments of the WDM transmission technologies and optical amplifiers, WDM networks have been studied extensively by many researchers. Interconnection of the WDM systems that are independently designed and constructed is required cost effectively. For the purpose of satisfying the requirements, several types of the wavelength conversion techniques have been studied. Fiber-optic four-wave mixing (FWM) based parametric wavelength conversion is one of the very promised techniques for applying to the broadband WDM networks because of its bit-rate transparency (response time˜100 fs), and its ability to process the multi-channels optical signals simultaneously. It is known that the FWM based parametric wavelength conversion is also realized in semiconductor optical amplifiers (SOA's). Since the multi-channels simultaneous wavelength conversion is realized by optical parametric processes in nonlinear media, it seems that so far most of the researchers have devoted to broaden the bandwidth of the wavelength conversion in wavelength domain to follow the increment of the extraordinary number of channels. However, from the practical point of view, not only the broadband multi-channels simultaneous wavelength conversion, but also different applications of the parametric wavelength conversion to the WDM networks should be conceived to enhance the flexibility of the signal processing.